[PATCH 2/2] [PATCH 2/2 v2] qe: add polling timeout to qe_issue_cmd()
From: Timur Tabi <hidden>
Date: 2009-05-26 15:23:27
Subsystem:
linux for powerpc (32-bit and 64-bit), the rest · Maintainers:
Madhavan Srinivasan, Linus Torvalds
The qe_issue_cmd() function (Freescale PowerPC QUICC Engine library) polls on a register until a status bit changes, but does not include a timeout to handle the situation if the bit never changes. Change the code to use the new spin_event_timeout() macro, which simplifies polling on a register without a timeout. Signed-off-by: Timur Tabi <redacted> --- This patch depends on my previous patch, "powerpc: introduce macro spin_event_timeout()". arch/powerpc/sysdev/qe_lib/qe.c | 9 ++++++--- 1 files changed, 6 insertions(+), 3 deletions(-)
diff --git a/arch/powerpc/sysdev/qe_lib/qe.c b/arch/powerpc/sysdev/qe_lib/qe.c
index 01bce37..05bdd43 100644
--- a/arch/powerpc/sysdev/qe_lib/qe.c
+++ b/arch/powerpc/sysdev/qe_lib/qe.c@@ -111,6 +111,7 @@ int qe_issue_cmd(u32 cmd, u32 device, u8 mcn_protocol, u32 cmd_input) { unsigned long flags; u8 mcn_shift = 0, dev_shift = 0; + u32 ret; spin_lock_irqsave(&qe_lock, flags); if (cmd == QE_RESET) {
@@ -138,11 +139,13 @@ int qe_issue_cmd(u32 cmd, u32 device, u8 mcn_protocol, u32 cmd_input) } /* wait for the QE_CR_FLG to clear */ - while(in_be32(&qe_immr->cp.cecr) & QE_CR_FLG) - cpu_relax(); + ret = spin_event_timeout((in_be32(&qe_immr->cp.cecr) & QE_CR_FLG) == 0, + 100, 0); + /* On timeout (e.g. failure), the expression will be false (ret == 0), + otherwise it will be true (ret == 1). */ spin_unlock_irqrestore(&qe_lock, flags); - return 0; + return ret == 1; } EXPORT_SYMBOL(qe_issue_cmd);
--
1.6.0.6